Performance and cost comparison of a FWS and a VSF constructed wetland system.

Two constructed wetland systems, treating domestic wastewater, are compared in terms of performance and costs. One is a free water surface (FWS) wetland system located in Pompia, Crete, south Greece, and the other one is a vertical subsurface flow (VSF) wetland system located in Comati, Chalkidiki, north Greece. The FWS system is designed for 1200 p.e. Its construction cost was Euro 305,000, and the capital, operation and maintenance cost was Euro 22.07 p.e.(-1) yr(-1) or Euro 0.50 m(-3) of influent. The VSF system is designed for 1000 p.e. Its construction cost was Euro 410,850, and the capital, operation and maintenance cost was Euro 36.81 p.e.(-1) yr(-1) or Euro 0.56 m(-3) of influent. Both systems achieved high removal rates for BOD5, COD, TSS, TKN, phosphorus, TC, and FC, which makes them ideal for small communities in the Mediterranean region.